Finding the Fourth Proportional to 2,643.69, 3,969.71 and 2,100.43

Step by Step Solution

1. Step 1: Write the proportion equation
   2,643.69 : 3,969.71 = 2,100.43 : x
2. Step 2: Convert to fraction form
   2,643.69/3,969.71 = 2,100.43/x
3. Step 3: Cross multiply
   2,643.69x = 3,969.71 × 2,100.43
4. Step 4: Simplify right side
   2,643.69x = 8,338,100.31
5. Step 5: Solve for x
   x = 8,338,100.31/2,643.69
6. Step 6: Final answer
   x = 3,153.97